Measuring the Cosmological Lepton Asymmetry through the Cosmic Microwave Background Anisotropy

1999/03/31 by William H. Kinney, Antonio Riotto · 5 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Neutrino Physics Research #Particle physics theoretical and experimental studies #astro-ph #hep-ph

paper · pdf · doi:10.1103/physrevlett.83.3366

published as Phys.Rev.Lett. 83 (1999) 3366-3369 · 4 pagex LaTex, 1 color postscript figure, uses epsf. Version submitted to PRL. (Bug in code fixed, new figure, conclusions unchanged)

arxiv created 1999/04/23 · openalex publication_date 1999/10/25 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

A large lepton asymmetry in the Universe is still a viable possibility and leads to many interesting phenomena such as gauge symmetry nonrestoration at high temperature. We show that a large lepton asymmetry changes the predicted cosmic microwave background (CMB) anisotropy in a dramatic way. Confusion with other cosmological parameters limits our ability to constrain the lepton asymmetry with current data. However, any degeneracy in the relic neutrino sea may be measured to a precision of a few percent when the CMB anisotropy is measured at the accuracy expected to result from the planned satellite missions MAP and Planck.

Cited by

• Expected signals in relic neutrino detectors
• Stringent constraints on cosmological neutrino-antineutrino asymmetries from synchronized flavor transformation
• Measuring the cosmological background of relativistic particles with the Wilkinson Microwave Anisotropy Probe
• Forecast on lepton asymmetry from future CMB experiments
• Unstable Superheavy Relic Particles as a Source of Neutrinos Responsible for Ultrahigh-Energy Cosmic Rays